When to replace fuel pump

Replace the fuel pump when it stops working. It is necessary to replace the entire fuel tank. The fuel pump is not a big problem with Prius.

If you want to replace parts proactively, look at the inverter coolant pump which should be replaced at 100K mile intervals. Look at the serpentine drive belt which should be replaced at the same interval, or when the engine coolant pump is replaced. If the engine coolant pump shows signs of coolant weeping out of the bearing, replace that. The 12V battery is another candidate for proactive replacement (like at 4 or 5 year intervals) unless you can be very alert to its condition (for example, by noticing the brightness of the cabin interior lights prior to starting the car) and can take action to replace the battery before it fails.

 

Will TS tell me whether it is the pump or the cassette in the fuse tray? I am not 100% sure it is the fuel delivery system, but I have pretty much ruled out everything else. The car WILL start for about 10 seconds and then stalls with check engine light and red triangle and the circle with exclamation point inside... I am sure it is starting for that short time and not just running the starter. Any direction from here, excluding towing it to a dealer, will be appreciated!

 

No. What is a cassette? Do you mean the integration relay located in the main relay/fuse box which contains the fuel pump circuit opening relay?

If you want to verify that 12V is getting to the fuel pump, the easiest approach would be to access the fuel pump connector. This means you have to remove the rear seat cushion, then remove the access cover on the body floor, then disconnect the fuel pump connector. Measure voltage across that connector while you are trying to start the engine.

Well, if you want proof that the engine is running, depress the accelerator pedal at the time that you believe it is running. Does the engine speed up? If it does not, that is proof the engine is just spinning because of MG1 rotating it.

Remove the air cleaner lid and stick your nose into the throttle body area. Are you overcome with the smell of unburnt gasoline? If you are not, then the fuel pump is not pumping. Also smell at the exhaust pipe for unburnt gasoline at that end.

If you hook up a fuel pressure gauge, it should measure at least 43 psi pressure.

 

Thank you Patrick. I will perform the voltage test on the fuel pump to see what's up. I am pretty sure that failed pump is my problem... Do you have any thoughts on a replacement tank/pump? I think i can get a used tank but not sure of the mileage. I might go with this if the mileage is not too much. I can get an aftermarket tank from Autozone. Then, of course, I can spend the big bucks and go to the dealer...

 

Yes, by cassette I meant the integrated fuse/relay in the main fuse box.
So Patrick where can I find out which 2 wires on the fuel pump plug to test? The plug has about 6 wires coming out of it and I want to make sure I am testing fuel pump alone. Thanks in advance!

 

I think you would have to consult the electrical wiring diagram, techinfo.toyota.com

If you decide to replace the fuel tank, a used unit would be reasonable to install.

 

With the rear seat removed you should be able to hear the fuel pump running especially with the cover off and maybe just by listening near the gas cap if you have good hearing. Just because it is running doesn't mean it is pumping at the proper pressure.
If Patrick's checks all go well and you still think it is the fuel pump you will have to take pressure readings.

 

I went ahead and tested the pump itself. Pin #3 and #7 to see if the fuel pump is actually woring. It's a no go. So I am thinking used fuel tank. Does that seem reasonable if not too many miles on the used tank/pump, etc? Thank YOU!

 

So you have power at the pins but the pump is not running?

 

Correct... Power to the pins but pump NOT running! That means I replace the whole assembly next, meaning the tank and pump and whole enchilada! Now how do I safely remove about 5 gallons of gasoline without spilling it all over myself?

 

Carefully.

I would to try and siphon out as much as you can. With that bladder your not going to get it all. Just try to reduce the weight of the tank to make it easier to handle. I had to change one once on my old Honda Accord (79) that had a hole in it.

 

Thanks Everyone! I installed the new tank and she started right up! It was not a huge job to replace the tank... I just don't reall like working around things that are flammable. Got her done Just in time to take her to DMV and get her registered for the new year.